Question

Question 2 33 pts TT T. An iron pipe is covered by ceramic insulation. The inner radius, ri of the metal pipe is equal to 0.04 m, while its outer radius, re, is equal to 0.10 m. On the other hand, the ceramic insulation has a thickness of 0.04 m. If the inner and outer temperatures, Ti and To, are kept constant at 400 K and 323 K respectively, find Tc in Kelvin. The length of the pipe is 10 m. Consider contact resistance between the ceramic and the iron. [use 2 decimal places when rounding off]

Answer 1

1 Roh 7 Calculate the net thermal resistance across the pipe. 1 In 2+ -In 2 2 tk L h;4 27k, Z In (rotta -In 2 tk, h (2007, ) 27tk L 7 1 11n 2 Lk hac k 1 1 1 1 In + ( + -In": +1 :) 1 1 1 0.10 0.04 -In 27(10)| (63) + -In (5000) (0.10 (20) 0.10+0.04 0.10 1 1 1 1 + -In (2.5)+ -In (1.4) 27(10)| (63) (500) (20) = 0.000531 K/W a(14) Calculate the net heat transfer rate across the pipe. (T-I)_(400–323) = 145009.42 W 145.01kW (0.000531)